In typical mail distribution operations at the various post offices worldwide, the metered and stamped mail is received in enormous volumes. In large mail distribution centers, if the mailpieces carry an imprinted indicia, the mailpieces are processed by sorters to sort the mail to its destination or in the event that the mailpiece has an affixed stamp, it is processed by the so-called facer-canceller which can orient the mailpiece cancel the stamp prior to the sorting of these mailpieces. In either case the actual weight of the mailpiece is normally never checked during the course of these operations.
As is well known in the United States and in many other countries, the postage amount required for delivery increases with the weight and size of the mailpiece. Accordingly, the Post Office will lose revenue on its delivery if in fact the postal rate (according to the postal Weight-Rate Tables) corresponding to the weight and/or size of the mailpiece exceeds the postage paid. In fact, one of the major factors contributing to loss of revenue is perceived to be the underpayment for individual mailpieces, and particularly those individual mailpieces being sent in batch mailings. In the conventional postal delivery systems, however, the costs associated with verifying the correct postage on an individual mailpiece may be prohibitive in terms of employee time since each piece to be verified must be manually extracted and individually weighed and rated either at entry into the mailstream or at some time during subsequent mail processing and delivery.
For batch mailings, there is normally a manual sampling and rating of mailpieces prior to merging them into the mailstream at the facility, but it will be appreciated that this sampling is at best inefficient because of possible human errors and the small sample size of such manual checking.
U.S. Pat. No. 5,072,400 to Mandulay discloses a system for monitoring the integrity of mail pieces passing through the delivery system for tracking and prevention of theft. In this system a data base is updated to include the initial weight and destination address of a mailpiece. As the mailpiece moves through the system the weight and the destination data are compared at the various stages to determine any discrepancies.
U.S. Pat. No. 5,019,991 to Sansone et.al., entitled CERTIFIED WEIGHER-SHORT PAID MAIL describes a system for assuring the post office that the weight of a mailpiece which would ordinarily require more postage was correctly accounted with consideration to other postage discounts, for example, number of mailpieces being sent to a particular ZIP-code. U.S. Pat. No. 5,008,827 to Sansone, et.al., entitled CENTRAL POSTAGE DATA COMMUNICATION NETWORK describes a user system for certifying by marking a pre-posted mailpiece that any required additional postage due on the mailpiece has been accounted for to the post office.
While each of these work well for the intended purposes, they do not address the problem of routinely assuring that mailpieces which may enter the mailstream at the post offices from the counter, letter boxes or in batch mailings carry sufficient postage. The teaching of the U.S. Pat. No. 5,072,400 also requires the use of extensive computer facilities for maintaining the database and for certifying and protecting the accounting for postage.